Prevalence of EBV, HPV and MMTV in Pakistani breast cancer patients: A possible etiological role of viruses in breast cancer

Triple Viral Infections in Advanced Breast Cancer: Insights from a Three-Case Report and Literature Review

Background and clinical significance: Viral infections are typically considered contributing or secondary factors in the development of breast cancer. Case presentation: This case report presents three instances of advanced breast cancer associated with triple viral infections. Case 1 involves a 78-year-old woman diagnosed with grade 2 invasive ductal carcinoma positive for HPV-18, CMV, and BLV. Case 2 describes a 39-year-old woman with grade 2 invasive ductal carcinoma, positive for HPV-16, CMV, and BLV. Case 3 is a 52-year-old woman with grade 3 invasive ductal carcinoma, positive for HPV-16, BLV, and MMTV. These cases suggest a possible correlation between viral co-infections and breast cancer aggressiveness, posing new questions about the role of viral infections in cancer development and prognosis. Conclusions: The findings contribute to growing evidence that viral infections may influence the progression and therapeutic response of breast cancer, warranting further investigation into targeted preventive measures including vaccinations.

Human papillomavirus E6 alters Toll-like receptor 9 transcripts and chemotherapy responses in breast cancer cells in vitro

BACKGROUND

Toll-like receptor 9 (TLR9) is a DNA recognizing receptor expressed also in several cancers. Decreased TLR9 expression is associated with poor prognosis in triple negative breast cancer (TNBC), but the role of TLR9 in breast cancer pathophysiology is currently unclear. Regulation of TLR9 expression in breast cancer is poorly understood. Human papillomavirus (HPV) infections suppress TLR9 expression in cervical cancers but the association between HPV and breast cancer has remained controversial. The aim of this study was to test if HPV16 can suppress TLR9 expression in breast cancer cells and affect cell behavior.

METHODS AND RESULTS

Human T-47D and MDA-MB-231 breast cancer cells were transduced with lentivirus encoding HPV16 E6 oncoprotein. The effects of E6 on TLR9 mRNA and protein expression, and cell proliferation, migration, invasion and sensitivity to chemotherapy were studied in vitro. Breast cancer tissue samples (n = 37) were analyzed for the presence of HPV DNA. E6 expression decreased TLR9 mRNA expression in MDA-MB-231 and T-47D cells in hypoxia. E6 expression altered breast cancer cell proliferation and made cells significantly less sensitive to the growth inhibitory effects of chemotherapeutic agents. HPV L1 gene was not detected in a small pilot cohort of clinical breast cancer specimens.

CONCLUSION

HPV16 may influence breast cancer cell TLR9 transcription and chemotherapy responses and could thereby affect breast cancer prognosis. These results suggest that HPV may have a previously unrecognized role in breast cancer pathophysiology and warrant further studies on the topic.

The association between infectious agents and breast cancer: a review of the epidemiologic evidence

PURPOSE

Several viruses have been casually linked to human cancers, including cervical, nasopharyngeal, liver, sarcoma, and Merkel cell carcinomas. However, the etiologic contribution of viral infections to breast cancer, the number one incident cancer among women worldwide, is not well established. Among studies exploring associations of viruses with breast cancer, potential linkages have been identified between breast cancer and five viruses: beta retrovirus, (i.e., mouse mammary tumor virus), human papillomavirus, Epstein Barr virus. bovine leukemia virus, and human cytomegalovirus.

METHODS

In this review, we provide a comprehensive evaluation of epidemiological ecologic, case-control, case-only, and cohort studies investigating these associations. We discuss results from several existing reviews and meta-analyses, evaluate epidemiological studies published in the past five years, and assess the relationship between these viruses and breast tumor clinicopathological factors.

RESULTS

The strongest epidemiological evidence for a viral role in breast cancer exists for MMTV and HPV, though limitations include lack of prospective studies for MMTV and potential detection bias in HPV studies. Viral detection challenges have limited studies of EBV and HCMV. Fewer studies have evaluated BLV, and though it has been associated with higher risk of breast cancer, sample sizes are quite small.   CONCLUSION: While epidemiologic evidence exists for an association between these five viruses and breast cancer, various methodological issues and lack of prospective studies preclude robust conclusions. Future research should prioritize establishing a temporal relationship between infection and disease, minimizing misclassification of detection assays, and further exploring the influence of co-infections.

The viral origins of breast cancer

During the past two decades evidence has been developed that indicates a handful of viruses with known oncogenic capacity, have potential roles in breast cancer. These viruses are mouse mammary tumour virus (MMTV - the cause of breast cancer in mice), high-risk human papilloma viruses (HPV-the cause of cervical cancer), Epstein Barr virus (EBV-the cause of lymphomas and naso-pharyngeal cancer) and bovine leukemia virus (BLV - the cause of cancers in cattle). These viruses may act alone or in combination. Each of these viruses are significantly more prevalent in breast cancers than in normal and benign breast tissue controls. The odds ratios for the prevalence of these viruses in breast cancer compared to normal and benign breast controls, are based on case control studies - MMTV 13·40, HPV 5.56, EBV 4·43 and BLV 2·57. The odds ratios for MMTV are much greater compared to the other three viruses. The evidence for a causal role for mouse mammary tumour virus and high risk for cancer human papilloma viruses in human breast cancer is increasingly comprehensive. The evidence for Epstein Barr virus and bovine leukemia virus is more limited. Overall the evidence is substantial in support of a viral cause of breast cancer.

High rate of high-risk human papillomavirus among benign and breast cancer patients in Ethiopia

INTRODUCTION

There have been numerous studies that showed the presence of human papillomavirus (HPV) in breast cancer; nonetheless, there is ongoing debate regarding their association. Given few studies in Ethiopia, we aimed to investigate the magnitude of HPV infection in Ethiopian breast cancer patients.

METHODS

A total of 120 formalin-fixed paraffin-embedded (FFPE) tissue blocks were obtained, and basic demographic, clinical, and histological data were collected from medical records. DNA was extracted from archived FFPE breast tissue specimens using GeneRead DNA FFPE Kit. The AnyplexTM II HPV28 Detection Kit (Seegene, Korea) was used to detect HPV by following the manufacturer's instructions. The SPSS Version 25 was used to enter and analyze data.

RESULTS

Among the 120 study participants; HPV (both high-risk and low-risk) was detected in 20.6% of breast cancer and 29.6% of non-malignant breast tumors. The most common genotype was the high-risk HPV 16 genotype. The frequency of HPV was nearly 10-fold higher in estrogen receptor-positive than ER-negative breast cancer. The percentage of HPV in the luminal (luminal A and luminal B) breast cancer subtypes was also much higher than in the non-luminal subtypes (HER-2 enriched and triple-negative breast cancer).

CONCLUSION

This study did not find a significant difference in HPV expression between breast cancer and non-malignant breast tumors; however, the higher percentage of HPV in ER-positive compared to ER-negative breast cancer warrants further attention.

Human papillomaviruses and breast cancer: A systematic review and meta‑analysis

Breast cancer (BC) is the leading malignancy worldwide. The association between human papillomavirus (HPV) and BC is debatable. The present systematic review and meta-analysis aimed to assess the prevalence of HPV DNA in malignant breast tumors. An extensive search of the PubMed and SCOPUS databases was carried out for case-control studies published between January 1, 2003 and January 7, 2023, which compared HPV DNA detection in breast tissue specimens of female patients with BC and women with absent or benign breast disorders. Once the initial title/abstract screening was completed by two independent investigators, the full texts of the included studies from that stage were reviewed by the aforementioned investigators to determine if they should be included in the present study. Data extraction was independently conducted by two investigators. A third investigator was consulted to resolve disagreements through free discussion. MedCalc was used for quantitative synthesis. The significance of association was estimated by pooled odds ratios (ORs) with 95% confidence intervals (CIs) calculated using the random-effects model. A total of 23 primary studies, including 3,243 subjects (2,027 patients and 1,216 controls), were eligible for quantitative analysis. HPV prevalence in patients with BC and controls was 21.95 and 8.96%, respectively. The prevalence of HPV differed significantly between the two groups (OR 3.83; 95% CI 2.03-7.25; P<0.01). Heterogeneity among studies was quantified using the I2 index which was 69.57% (95% CI 51.89-80.75). The risk of bias was assessed using an appropriate tool contributed by the CLARITY Group at McMaster University. Seven studies had a low risk of bias, 15 studies had a moderate risk of bias and only one study had a serious risk of bias. These results reinforce the hypothesis that HPV is involved in BC development and progression, indicating a possible role of HPV vaccination in BC prevention.

Global epidemiology of breast cancer based on risk factors: a systematic review

BACKGROUND

Numerous reviews of the epidemiology and risk factors for breast cancer have been published previously which heighted different directions of breast cancer.

AIM

The present review examined the likelihood that incidence, prevalence, and particular risk factors might vary by geographic region and possibly by food and cultural practices as well.

METHODS

A systematic review (2017-2022) was conducted following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, reporting on epidemiological and risk factor reports from different world regions. Medical Subject Heading (MeSH) terms: "Breast neoplasm" "AND" country terms such as "Pakistan/epidemiology", "India/epidemiology", "North America/epidemiology", "South Africa/epidemiology" were used to retrieve 2068 articles from PubMed. After applying inclusion and exclusion terms, 49 papers were selected for systematic review.

RESULTS

Results of selected articles were summarized based on risk factors, world regions and study type. Risk factors were classified into five categories: demographic, genetic and lifestyle risk factors varied among countries. This review article covers a variety of topics, including regions, main findings, and associated risk factors such as genetic factors, and lifestyle. Several studies revealed that lifestyle choices including diet and exercise could affect a person's chance of developing breast cancer. Breast cancer risk has also been linked to genetic variables, including DNA repair gene polymorphisms and mutations in the breast cancer gene (BRCA). It has been found that most of the genetic variability links to the population of Asia while the cause of breast cancer due to lifestyle modifications has been found in American and British people, indicating that demographic, genetic, and, lifestyle risk factors varied among countries.

CONCLUSION

There are many risk factors for breast cancer, which vary in their importance depending on the world region. However, further investigation is required to better comprehend the particular causes of breast cancer in these areas as well as to create efficient prevention and treatment plans that cater to the local population.

The prevalence of varicella zoster virus, herpes simplex virus type 2, and human papillomavirus in breast cancerous tissues and their adjacent ones in Iran

Background

Breast cancer is the second type of cancer in the world. Some internal and external risk factors, especially infection diseases, can progress breast cancer. As the relation between varicella zoster virus (VZV), human papillomavirus (HPV), herpes simplex virus type 2 (HSV-2), and breast cancer has not been understood, it was attempting to find the effect of these viruses and breast cancer in this study.

Materials and Methods

We collected 40 breast cancer and 50 healthy adjacent tissues from Taleghani and Imam Hossein Hospital, Tehran, Iran, in 3 years starting in 2017. After extracting DNA from breast tissues, multiplex polymerase chain reaction (PCR), nested PCR, and PCR were done to analyze the prevalence of HSV-2, VZV, and HPV.

Results

Our results showed that HPV may be one of the important causes of breast cancer. Nested PCR illustrated nine breast cancerous tissues (mean age: 43) and three healthy adjacent ones (mean age: 41) were infected by HPV. Phylogenetic analysis illustrated that all of the infected HPV cancerous and healthy tissues were HPV 18 (except two healthy samples infected with HPV 6). Nevertheless, there were not any infected tissues by HSV-2 and VZV.

Conclusion

It seems that HPV virus type 18 can have high prevalence in breast cancerous tissues in comparison with healthy adjacent ones, and it is likely to have an effect on breast cancer progression. However, the opposite trend is true for HSV-2 and VZV as we did not find any differences between different kinds of breast tissues.

An updated systemic review and meta-analysis on human papillomavirus in breast carcinogenesis

Background

Breast Cancer (BC) stands out as the widely prevalent malignancy among all the types of cancer affecting women worldwide. There is significant evidence that the pathogenicity of BC may be altered by Human Papillomavirus (HPV) infection; however, conclusive data are not yet available.

Methods

By searching five databases, including EMBASE, IBECS, PubMed, Scopus, Science Direct, Google Scholar, and Web of Science, a thorough systematic analysis was conducted on the prevalence of HPV in BC patients from 1990 to June 30, 2022. After applying extensive eligibility criteria, we selected 74 publications for further analysis based on the prevalence of HPV infections in breast tissues. All of the data were analyzed using a random-effects meta-analysis, Cochran Q test and I2 statistic were used to calculate the heterogeneity of the prevalence among these studies using subgroup analysis. Variations in the HPV prevalence estimates in different subgroups were evaluated by subgroup meta-analysis.

Results

In total, 3156 studies were initially screened, resulting in 93 full-text studies reviewed, with 74 meeting inclusion criteria. Among a total of 7156 BC biopsies, the pool prevalence of HPV was 25.6% (95% CI= 0.24-0.33, τ2 = 0.0369 with significant heterogeneity between estimates (I 2 = 97% and p< 0.01). Consequently, 45 studies with available controls were further studied, and the prevalence of HPV in case-control studies was 26.2% with overall odds 5.55 (95% CI= 3.67-8.41, I 2 = 38%, τ2 = 1.4878, p< 0.01). Further subgroup analysis of HPV revealed HPV-16 had a maximum prevalence of 9.6% (95% CI= 3.06-11.86, I 2 = 0%, τ2 = 0.6111, p< 0.01). Among different geographical regions, Europe reported the maximum prevalence of HPV, i.e., 39.2% (95% CI=1.29-7.91, I 2 = 18%, τ2 = 1.2911, p< 0.01). Overall distribution showed HPV-18 was a frequent HPV subtype reported in Australia.

Conclusion

Current study provides a global estimate of HPV prevalence in BC patients and demonstrates a significant association between this virus and BC etiology. Nevertheless, we recommend further investigation into the underlying mechanism is essential to validate this hypothesis.

Epstein-Barr virus in breast carcinoma and in triple negative cases impact on clinical outcomes

BACKGROUND

The contribution of viral infection in tumors pathogenesis has currently attracted attention. Epstein-Barr virus is an infectious agent involved in numerous human malignancies, including breast cancer. Although, their prognostic impact in breast tumor is rarely investigated. Therefore, we sought in our study to evaluate the prevalence of EBV in Tunisian breast carcinoma and to examine their potential association with clinicopathological features and overall survival.

METHODS

Our retrospective study included 100 formalin fixed paraffin embedded samples from Tunisian breast carcinoma. EBV infection was evaluated by immunohistochemical analysis, using monoclonal antibody against latent membrane protein 1 (LMP-1) and polymerase chain reaction. A subset of PCR positive specimens was subjected to in situ hybridization for the detection of EBER expression. Biomarker's expression was evaluated by immunohistochemistry method. Statistical analysis was also explored.

RESULTS

The expression status of ER, PR and HER2 was 81%, 71.4% and 33.7% respectively. The triple negative profile was present in 10.84% of cases. LMP-1 expression was negative in all breast cancer specimens. PCR assay showed that 44% of patients were positive for EBV genome. None of the 15 PCR positive cases showed positive results for EBV by ISH. According to the molecular phenotype, there was a statistically significant difference in EBV DNA prevalence between breast cancer subgroups including TN (67%), Lum B (64%), HER2 + (50%) and Lum A (30%). Bivariate analysis showed that EBV DNA was significantly associated with HER2 + (p = 0.035), tumor size (p = 0.018) and high SBR grade (p = 0.009). Multiple logistic regression analysis confirms the positive correlation of EBV with tumor size (p = 0.048) and SBR grade (p = 0.042). Kaplan-Meier analysis showed that patients with EBV+ had significantly shorter overall survival than those with EBV- (p = 0.032).

CONCLUSIONS

Our study demonstrated the presence of EBV DNA in Tunisian breast carcinoma. EBV DNA was associated with aggressive features and poor overall survival. Further investigations will be required in large samples size to clarify the potential role of EBV in breast tumor progression.

HPV-Associated Breast Cancer: Myth or Fact?

Some estimates place the proportion of human malignancies attributable to viruses at between 15 and 20 percent. Viruses including the human papillomavirus are considered an interesting but controversial etiological risk factor for breast cancer. HPV infection is anticipated to be an early trigger in breast cancer carcinogenesis, followed by cumulative alterations over time ("hit and run" mechanism) through synergy with other environmental factors. The association between HPV and breast cancer has not yet been verified. There are very conflicting data on the presence of HPV DNA in breast cancer samples, and we lack a clarified, exact mode of HPV transmission to the breast. In our review article we analyzed the up-to-date knowledge about the association of HPV and breast cancer. Furthermore, we summarized the available original research published since 2010. In conclusion, the complexity and inconsistency of the available results together with the relatively low prevalence of HPV infection requires extensive research with much larger studies and exact and unified diagnostic methods are required to better understand the role of the HPV in breast carcinogenesis.

Presence of Human Papillomavirus DNA in Malignant Neoplasia and Non-Malignant Breast Disease

Breast cancer is the leading cause of cancer death among women worldwide. Multiple extrinsic and intrinsic factors are associated with this disease’s development. Various research groups worldwide have reported the presence of human papillomavirus (HPV) DNA in samples of malignant breast tumors. Although its role in mammary carcinogenesis is not fully understood, it is known that the HPV genome, once inserted into host cells, has oncogenic capabilities. The present study aimed to detect the presence of HPV DNA in 116 breast tissue biopsies and classify them according to their histology. It was found that 50.9% of the breast biopsies analyzed were malignant neoplasms, of which 74.6% were histologically classified as infiltrating ductal carcinoma. In biopsies with non-malignant breast disease, fibroadenoma was the most common benign neoplasm (39.1%). Detection of HPV DNA was performed through nested PCR using the external primer MY09/11 and the internal primer GP5+/6+. A hybridization assay genotyped HPV. HPV DNA was identified in 20.3% (12/59) of malignant neoplasms and 35% non-malignant breast disease (16/46). It was also detected in 27.3% (3/11) of breast tissue biopsies without alteration. However, there are no statistically significant differences between these groups and the existence of HPV DNA (p = 0.2521). Its presence was more frequent in non-malignant alterations than in malignant neoplasias. The most frequent genotypes in the HPV-positive samples were low-risk (LR) HPV-42 followed by high-risk (HR) HPV-31.

The Viral Origin of Human Breast Cancer: From the Mouse Mammary Tumor Virus (MMTV) to the Human Betaretrovirus (HBRV)

A Human Betaretrovirus (HBRV) has been identified in humans, dating as far back as about 4500 years ago, with a high probability of it being acquired by our species around 10,000 years ago, following a species jump from mice to humans. HBRV is the human homolog of the MMTV (mouse mammary tumor virus), which is the etiological agent of murine mammary tumors. The hypothesis of a HMTV (human mammary tumor virus) was proposed about 50 years ago, and has acquired a solid scientific basis during the last 30 years, with the demonstration of a robust link with breast cancer and with PBC, primary biliary cholangitis. This article summarizes most of what is known about MMTV/HMTV/HBRV since the discovery of MMTV at the beginning of last century, to make evident both the quantity and the quality of the research supporting the existence of HBRV and its pathogenic role. Here, it is sufficient to mention that scientific evidence includes that viral sequences have been identified in breast-cancer samples in a worldwide distribution, that the complete proviral genome has been cloned from breast cancer and patients with PBC, and that saliva contains HBRV, as a possible route of inter-human infection. Controversies that have arisen concerning results obtained from human tissues, many of them outdated by new scientific evidence, are critically discussed and confuted.

Association of human papillomavirus with breast cancer: a new perspective on an old debate

Breast cancer is a common cancer in the female population. Despite remarkable progress in the treatment of this cancer, its exact etiology is still unknown. Since the first evidence of an association between breast cancer and human papillomavirus (HPV) was provided in 1992, numerous studies have explored this subject but have reached contradictory results. In this review, the authors examine the existing evidence and hypotheses regarding the pathways whereby HPV infection can reach breast cells and the mediators linking HPV oncoproteins to breast cancer pathogenesis. Furthermore, the authors discuss contradictory findings regarding the association of HPV with breast cancer. Showing the link between HPV infection and increased genomic instability, reduced apoptosis, immune system dysfunction and progression of metastasis, the reviewed findings highlight the importance of active presence or history of HPV infection as a prognostic factor for breast tumor development.

Prevalence and Current Scenario of HPV in Pakistan: A Systematic Review and Meta-analysis

AIM: The present study was designed to compile and screen data regarding HPV-related reported diseases to evaluate the status of HPV infection in Pakistan. METHODS: The literature on the prevalence of HPV in Pakistan was searched in Google Scholar and other search engines using various keywords. RESULTS: A total of 39 studies published from 2007 to 2018 were reviewed. About 7341 participants have been screened for HPV in Pakistan for the past 11 years, and according to this meta-analysis, the reported HPV prevalence was 23.1%. The highest HPV prevalence rate was observed among cervical cancer cases (80.4%) followed by normal cervical region (61.8%) and oral cancer (40.4%), respectively. CONCLUSION: The high prevalence of HPV in Pakistan reflects the raised burden of HPV-associated diseases. The health-care system needs to be more organized in terms of awareness and screening programs, diagnosis, and treatment of the disease to reduce the burden of HPV in Pakistan.

Interrelated Oncogenic Viruses and Breast Cancer

Breast Cancer is a multifactorial disease and recent evidence that viruses have a greater role in its aetiology and pathophysiology than previously hypothesized, has garnered a lot of attention in the past couple of years. After the role of Mouse Mammary Tumour Virus (MMTV) in the oncogenesis of breast cancer has been proved in mice, search for similar viruses found quite a plausible relation of Human Papilloma Virus (HPV), Epstein–Barr virus (EBV), and Bovine Leukaemia Virus (BLV) with breast cancer. However, despite practical efforts to provide some clarity in this issue, the evidence that viruses cause breast cancer still remains inconclusive. Therefore, this article aims to clarify some ambiguity and elucidate the correlation of breast cancer and those particular viruses which are found to bring about the development of tumorigenesis by a previous infection or by their own oncogenic ability to manipulate the molecular mechanisms and bypass the immune system of the human body. Although many studies have reported, both, the individual and co-existing presence of HPV, EBV, MMTV, and BLV in patient sample tissues, particularly in Western women, and proposed oncogenic mechanisms, majority of the collective survey of literature fails to provide a delineated and strong conclusive evidence that viruses do, in fact, cause breast cancer. Measures to prevent these viral infections may curb breast cancer cases, especially in the West. More studies are needed to provide a definite conclusion.

Breast Cancer Risk and Human Papillomavirus Infection: A Bradford Hill Criteria Based Evaluation

BACKGROUND

The association between human papillomavirus (HPV) and human breast cancer (BC) has already been thoroughly studied worldwide with contradictory findings. Although the researchers have tried to minimize the conflict using statistical meta-analysis, because of its shortcomings, there is still a need to evaluate the correlation between HPV and BC using any additional method.

OBJECTIVES

This study was launched to investigate the correlation between HPV and BC through the application of Bradford Hill criteria postulates.

METHODS

Population-wide studies associating HPV with BC were searched using the PubMed database. Then, the information of HPV burden in BC, normal/benign samples was analyzed, and ultimately Bradford Hill criteria postulates were applied on the collected evidence to explore the relationship between HPV and BC. In addition, to make the outcomes more authentic, we also reviewed the methodologies of previous studies to address the propensity of false results.

RESULTS

After a careful evaluation of the obtained data against major Bradford Hill criteria postulates, it was noted that all these postulates including strength, consistency, biological gradient, temporality, plausibility, experiment, specificity, and analogy were not fulfilled.

CONCLUSION

The results of the present study have failed to establish a casual association between HPV and BC rather suggested HPV as a cause-effective agent or at least a co-participant in the pathogenesis of BC. The weakness of association especially the low level of consistency across studies, and the lack of specificity of effect, there is a need for more experiments concerning Bradford Hill criteria postulates.

Implications of viral infection in cancer development

Since the identification of the first human oncogenic virus in 1964, viruses have been studied for their potential role in aiding the development of cancer. Through the modulation of cellular pathways associated with proliferation, immortalization, and inflammation, viral proteins can mimic the effect of driver mutations and contribute to transformation. Aside from the modulation of signaling pathways, the insertion of viral DNA into the host genome and the deregulation of cellular miRNAs represent two additional mechanisms implicated in viral oncogenesis. In this review, we will discuss the role of twelve different viruses on cancer development and how these viruses utilize the abovementioned mechanisms to influence oncogenesis. The identification of specific mechanisms behind viral transformation of human cells could further elucidate the process behind cancer development.

Prevalence and characteristics of mouse mammary tumor virus-like virus associated breast cancer in China

BACKGROUND

Despite extensive molecular epidemiological studies, the prevalence and characteristics of Mouse Mammary Tumor Virus-Like Virus (MMTV-LV) in Chinese women breast cancer are still unclear. Besides, the prevalence of MMTV-LV in women breast cancer tissue varies in different countries and its dependent factors remain inconclusive.

METHODS

In the first part of the study, a case-control study was performed. 119 breast cancer samples (84 from Northern China and 35 from Southern China) and 50 breast fibroadenoma specimens were collected from Chinese women patients. MMTV-like env sequence and the homology to MMTV env gene were analysed by semi-nested polymerase chain reaction (PCR). We also explored the association of MMTV-LV prevalence with sample sources (Southern and Northern China) and patients' clinicopathological characteristics. To investigate the dependent factors of the prevalence of MMTV-LV in breast cancer worldwide, a meta-analysis was conducted in the second part of the study.

RESULTS

We found that the prevalence of MMTV-LV was much higher in breast cancer tissues (17.65%) than that in breast fibroadenoma specimens (4.00%) (P < 0.05). MMTV-LV prevalence in Chinese women breast cancer tissues was significantly different between Southern China (5.71%) and Northern China (22.62%) (P < 0.05). The prevalence of MMTV-LV also associates significantly with expression of HER2, but shows no significant correlation with other parameters. In the meta-analysis, we found that MMTV-LV prevalence in breast cancer tissue was dependent on the distribution of M. domesticus mouse (M. d), M. musculus mouse (M.m) and M.castaneus mouse (M.c) worldwide (P < 0.05).

CONCLUSION

The distribution of house mice may be a crucial environmental factor that explains the geographic differences in human breast cancer incidence. Our findings may provide a potential avenue of prevention, diagnosis and treatment for breast cancer.

Presence of HPV, EBV and HMTV Viruses Among Egyptian Breast Cancer Women: Molecular Detection and Clinical Relevance

Background

Oncogenic viruses, their possible association with breast cancer (BC) and effect on its clinical course are interesting issue. The present study evaluates the presence of human papillomavirus (HPV), EpsteinBarr virus (EBV), and human mammary tumor virus (HMTV) in BC and their relation with clinico-pathological characteristics.

Patients and Methods

This study was conducted on 80 Egyptian women with BC and 30 control women without known oncological disease. Forty formalin-fixed paraffin-embedded (FFPE) tissues, forty fresh tissue samples, and white blood cells (WBCs) of BC patients and WBCs of controls were subjected to a qualitative polymerase chain reaction (PCR). Quantitative real-time PCR was used to measure viral loads in fresh tissues of BC. The result was correlated with clinico-pathological characteristics of BC.

Results

HPV was detected in 33 (41.25%), EBV in 30 (37.5%) and HMTV in 33 (41.25%) BC patients. None of the control women was positive for HPV or EBV while HMTV was detected in 7 (23.3%). Among 40 BC WBCs specimens, HPV/HMTV were found together in 25%, followed by EBV/HMTV in 2.5% and EBV/HPV in 2.5%. However, the three viruses (HPV/EBV/HMTV) were found together in only 5%. In the 40 fresh BC tissues, the three viruses were found together in 12 (30%), EBV/HMTV in 7 (17.5%), HPV/HMTV in 4 (10%), and HPV/EBV in 4 (10%). EBV, HMTV, or multiple viral infections were associated with younger age of BC women. HPV, EBV, and HMTV median loads in fresh tissues were 4.8×10³ copies/μL, 6.3×10³ copies/μL, and 97 copies/μL, respectively.

Conclusion

WBCs could be a more suitable specimen instead of fresh tissue for HMTV detection in BC patients to avoid invasive procedures. The presence of HPV, EBV, and HMTV together in Egyptian women with BC was significantly associated with younger age.

Tumor-related Microbiome in the Breast Microenvironment and Breast Cancer

Despite the significant progress in diagnosis and treatment over the past years in the understanding of breast cancer pathophysiology, it remains one of the leading causes of mortality worldwide among females. Novel technologies are needed to improve better diagnostic and therapeutic approaches, and to better understand the role of tumor-environment microbiome players involved in the progression of this disease. The gut environment is enriched with over 100 trillion microorganisms, which participate in metabolic diseases, obesity, and inflammation, and influence the response to therapy. In addition to the direct metabolic effects of the gut microbiome, accumulating evidence has revealed that a microbiome also exists in the breast and in breast cancer tissue. This microbiome enriched in the breast environment and the tumor microenvironment may modulate effects potentially associated with carcinogenesis and therapeutic interventions in breast tissue, which to date have not been properly acknowledged. Herein, we review the most recent works associated with the population dynamics of breast microbes and explore the significance of the microbiome on diagnosis, tumor development, response to chemotherapy, endocrine therapy, and immunotherapy. To overcome the low reproducibility of evaluations of tumor-related microbiome, sequencing technical escalation and machine deep learning algorithms may be valid for standardization of assessment for breast-related microbiome and their applications as powerful biomarkers for prognosis and predictive response in the future.

High-risk human papillomaviruses and Epstein-Barr virus in breast cancer in Lebanese women and their association with tumor grade: a molecular and tissue microarray study

Background

High-risk human papillomaviruses (HPVs) are present and can cooperate with Epstein–Barr virus (EBV) to initiate and/or enhance the progression of several types of human carcinomas including cervical as well as head and neck; in parallel, it has been recently pointed out that these oncoviruses can be detected in human breast cancers. Thus, we herein explored the presence/co-presence of high-risk HPVs and EBV in breast cancer in Lebanese women.

Methods

A cohort of 102 breast cancer samples and 14 normal breast tissues were assessed for the presence of HPVs and EBV. Polymerase chain reaction (PCR) and immunohistochemistry (IHC) analysis in addition to tissue microarray (TMA) platform were used in this study.

Results

We found the presence of HPV in 66/102 (65%) of our samples, while EBV is present in 41/102 (40%) of the cohort. Additionally, our data showed that high-risk HPV types (52, 35, 58, 45, 16 and 51) are the most frequent in breast cancer in Lebanese women. Meanwhile, we report that high-risk HPVs and EBV are co-present in 30/102 (29%) of the samples; more significantly, our results indicate that their co-presence is associated with tumor grade (p = 0.03).

Conclusion

Our data revealed that HPVs and EBV are present/co-present in human breast cancer where they may play an important role in its development and/or progression; thus, we believe that further investigations are essential to confirm and elucidate the presence/co-presence of these oncoviruses and the underlying mechanisms of their interaction in breast carcinogenesis.

Oncogenic human papillomavirus in breast cancer: molecular prevalence in a group of Congolese patients

Background

Since the work of Band et al. in 1990 (Proc. Natl. Acad. Sci. USA 87:463–467), several studies have suggested a possible link between the pathogenesis of breast cancer and viral infection. Infection with oncogenic HPV has been one of the viruses implicated in breast cancer cases worldwide.

Objective

To investigate the presence of HPV DNA in archived paraffin-embedded breast cancer cases at the University Hospital of Brazzaville and to assess the association between viral HPV infections and clinicopathological features.

Methods

A total of 40 formalin-fixed paraffin-embedded (FFPE) biopsies were retrospectively collected and available information was recorded. HPV detection and genotyping were performed by real-time PCR by GeneXpert technology (Cepheid, Sunnyvale, USA).

Results

The mean age was 51.1±11.4 years (range 22–75 years; median was 47). Overall, HPV DNA was detected in six (15%) breast carcinoma samples. HPV-16, the most common genotype was identified in 83.7 % of all samples. HPV porting with clinicopathological features showed no significant difference (P>0.05). However, a statistically significant difference was observed between HPV infection and SBR grade (P=0.05).

Conclusion

Our study described a high prevalence of HPV-HR in breast cancer cases in the Congolese woman. Future type case-control studies are necessary to better describe the potential role of HPV in the occurrence of breast cancer in Congo.

Downregulation of miR-143/145 Cluster in Breast Carcinoma Specimens: Putative Role of DNA Oncoviruses

Background: The DNA oncoviruses, including human papillomavirus (HPV) and Epstein-Barr virus (EBV) are among the most important infectious agents involved in breast carcinogenesis. These oncoviruses have a broad disrupting effect on cellular miRNAs and their functions, by which they contribute to carcinogenesis. Objectives: In this investigation, we evaluated the correlation between HPV and EBV and the expression level of tumor suppressor miRNAs (miR-143 and 145), clinical outcomes, and their association with stimulating inflammatory cytokines in patients with breast carcinoma. Methods: In our case-control study, 35 cancerous tissues and 35 adjacent non-cancerous tissues were collected from 35 patients. Nested-PCR was set up for the detection of HPV and EBV genomes, and RT-qPCR was used for miRNA expression in the case and control groups. In addition, serum specimens were obtained from all patients (n = 35) and healthy controls (n = 35) to determine the IL-8 serum concentration. Results: We found HPV and EBV in 14.2% (10/70) and 7% (5/70) of all samples, respectively. The distributions of positive samples in the case and control groups were 25.7% (9/35) and 2.9% (1/35) (P = 0.006) for HPV and 11.4% (4/35) and 2.9% (1/35) (P = 0.164) for EBV, respectively. Besides, RT-qPCR showed that miR-143 and miR-145 were significantly downregulated in HPV and EBV-infected cases compared to non-infected ones (P < 0.05). Data also indicated that the promotion of metastasis status was related to miR-143/145 downregulation and HPV infection (P = 0.003). No significant difference was found in serum IL-8 concentration concerning viral infections. Conclusions: Our results suggested the possible involvement of viral infections in breast carcinogenesis and adverse clinical outcomes by downregulating miR-143/145.

Oncoproteins of High-Risk HPV and EBV Cooperate to Enhance Cell Motility and Invasion of Human Breast Cancer Cells via Erk1/Erk2 and β-Catenin Signaling Pathways

Breast cancer is a leading cause of death in women around the world. Most breast cancer-related deaths are a result of complications from the metastatic spread. Several recent studies reported that high-risk human papillomaviruses (HPVs) and Epstein-Barr virus (EBV) are co-presented in different types of human carcinomas including breast; however, the cooperative effects between high-risk HPVs and EBV oncoproteins in human breast cancer have not been investigated yet. Thus, we herein explored the cooperation outcome between E6/E7 and latent membrane protein 1 (LMP1) oncoproteins of high-risk HPV type 16 and EBV, respectively, in two human breast cancer cell lines, MCF7 and MDA-MB-231. Our data revealed that the cooperation of E6/E7 and LMP1 oncoproteins stimulates cell proliferation and deregulates cell cycle progression of human breast cancer and normal mammary cells; in parallel, we noted that E6/E7/LMP1 incite colony formation of both breast cancer cell lines but not normal cells. More significantly, our results point out that the co-expression of E6/E7 and LMP1 oncoproteins enhances cell motility and invasion of MCF7 and MDA-MB-231 cell lines; this is accompanied by deregulation of epithelial-mesenchymal transition biomarkers including E-cadherin, β-catenin, fascin, and vimentin. The molecular pathway analysis of HPV and EBV oncoproteins cooperation shows that it can enhance the phosphorylation of extracellular signal-regulated kinases (Erk1/Erk2) in addition to β-catenin, which could be behind the effect of this cooperation in our cell models. The study clearly suggests that high-risk HPV and EBV coinfection can play an important role in breast cancer progression via Erk1/Erk2 and β-catenin signaling pathways.

Human Mammary Tumor Virus, Human Papilloma Virus, and Epstein-Barr Virus Infection Are Associated With Sporadic Breast Cancer Metastasis

Background

Viral cause of sporadic breast cancer (SBC) has been suggested based on the experimental murine model of mammary tumor caused by mouse mammary tumor virus (MMTV), Epstein-Barr virus (EBV), and human papillomavirus (HPV). While some studies have demonstrated the presence of viral sequences of MMTV, HPV, and EBV in breast cancer cells, others failed. These contradictions may be attributed to the geographical distribution of breast cancer incidence and/or technical variations. In the current study, we aimed to investigate the correlation of MMTV, HPV, and EBV infections with the development of breast cancer in Jordanian patients.

Methods

One hundred SBC tissue samples were subjected to laser capture microdissection for the selection of tumor cells populations. Fluorescence polymerase chain reaction (PCR) was used to detect the presence of the MMTV env-like sequences. Real-time PCR was used for HPV and EBV detection, and EBV was further confirmed by chromogen in situ hybridization (CISH).

Results

Mouse mammary tumor virus, HPV, and EBV were detected in SBC in 11%, 21%, and 23%, respectively. Only 3 of 52 (5.7%) positive cases demonstrated multiple virus infections. However, 49 of 52 (94%) of the positive cases revealed the presence of 1 type of viral sequences. Consequently, 52% of the studied breast cancer cases were infected with at least 1 type of the aforementioned viruses.

Conclusions

The current cohort suggests that MMTV, HPV, and EBV have a potential role in the development of breast cancer and adding more reasons to proceed with the quest of a possible viral origin of breast cancer.

Human Mammary Tumor Virus, Human Papilloma Virus, and Epstein-Barr Virus Infection Are Associated With Sporadic Breast Cancer Metastasis

BACKGROUND

Viral cause of sporadic breast cancer (SBC) has been suggested based on the experimental murine model of mammary tumor caused by mouse mammary tumor virus (MMTV), Epstein-Barr virus (EBV), and human papillomavirus (HPV). While some studies have demonstrated the presence of viral sequences of MMTV, HPV, and EBV in breast cancer cells, others failed. These contradictions may be attributed to the geographical distribution of breast cancer incidence and/or technical variations. In the current study, we aimed to investigate the correlation of MMTV, HPV, and EBV infections with the development of breast cancer in Jordanian patients.

METHODS

One hundred SBC tissue samples were subjected to laser capture microdissection for the selection of tumor cells populations. Fluorescence polymerase chain reaction (PCR) was used to detect the presence of the MMTV env-like sequences. Real-time PCR was used for HPV and EBV detection, and EBV was further confirmed by chromogen in situ hybridization (CISH).

RESULTS

Mouse mammary tumor virus, HPV, and EBV were detected in SBC in 11%, 21%, and 23%, respectively. Only 3 of 52 (5.7%) positive cases demonstrated multiple virus infections. However, 49 of 52 (94%) of the positive cases revealed the presence of 1 type of viral sequences. Consequently, 52% of the studied breast cancer cases were infected with at least 1 type of the aforementioned viruses.

CONCLUSIONS

The current cohort suggests that MMTV, HPV, and EBV have a potential role in the development of breast cancer and adding more reasons to proceed with the quest of a possible viral origin of breast cancer.

The co-presence of high-risk human papillomaviruses and Epstein-Barr virus is linked with tumor grade and stage in Qatari women with breast cancer

High-risk human papillomaviruses (HPV) can be present and cooperate with Epstein–Barr virus (EBV) to promote the onset and/or progression of various cancers including cervical, breast, head and neck as well as colorectal. In this investigation, we explored the co-prevalence of high-risk HPV and EBV in 74 breast cancer tissues from Qatari women using polymerase chain reaction. We found that high-risk HPV and EBV are present in 48/74 (65%) and 36/74 (49%) of the cases, respectively. While we noted that the presence of HPV presence is associated with triple-negative breast cancer (TNBC) (p = .008), however, the presence of EBV did not correlate with any breast cancer subgroup. Moreover, our data revealed that high-risk HPV and EBV are co-present in 35/74 (47%) of the samples and their co-presence is significantly associated with tumor grade (p = .04) and tumor stage (p = .04). These data indicate that HPV and EBV are commonly co-present in breast cancer and their association could be linked with a more aggressive tumor phenotype. Thus, further investigations are essential to understand the underlying mechanisms of HPV and EBV cooperation in breast carcinogenesis.

WITHDRAWN: Application of Echocardiography Information Technology in Monitoring Cardiac Function and Peripheral Neurotoxicity of HPV Patients Infected with Breast Cancer after Chemotherapy

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Human Papillomaviruses and Epstein-Barr Virus Interactions in Colorectal Cancer: A Brief Review

Human papillomaviruses (HPVs) and the Epstein-Barr virus (EBV) are the most common oncoviruses, contributing to approximately 10%-15% of all malignancies. Oncoproteins of high-risk HPVs (E5 and E6/E7), as well as EBV (LMP1, LMP2A and EBNA1), play a principal role in the onset and progression of several human carcinomas, including head and neck, cervical and colorectal. Oncoproteins of high-risk HPVs and EBV can cooperate to initiate and/or enhance epithelial-mesenchymal transition (EMT) events, which represents one of the hallmarks of cancer progression and metastasis. Although the role of these oncoviruses in several cancers is well established, their role in the pathogenesis of colorectal cancer is still nascent. This review presents an overview of the most recent advances related to the presence and role of high-risk HPVs and EBV in colorectal cancer, with an emphasis on their cooperation in colorectal carcinogenesis.

Prevalence of Epstein-Barr virus (EBV) in Iranian Breast Carcinoma Patients

Introduction:

Breast cancer (BC) is the most common malignancy affecting females worldwide. Various risk factors play a role in the developing of BC. Infectious agents like viruses have been proposed for this cancer and Epstein-Barr virus (EBV) is a widely researched candidate virus. This study detects the presence of EBV-DNA in breast cancer patients.

Methods:

The study was conducted on 59 formalin-fixed paraffin-embedded (FFPE) tissue blocks samples of women with breast carcinoma and 11 non-neoplastic breast controls. The DNA was extracted for all the samples. Then detection of EBNA1 EBV was done by polymerase chain reaction (PCR).

Results:

EBV was detected in 6.7% (4/59) of patients while all breast control samples were negative. All patients with positive EBV-DNA were high tumor grades (II, and III). Also, they had a low level of educations.

Conclusions:

According to our findings, it can be suggested that EBV may have a potential role in breast cancer development. However, this study provides substantial but not conclusive evidence for the involvement of viruses in BC disease development. Therefore, future investigations are needed to elucidate the exact role of EBV in breast cancer.

Epstein-Barr Virus Infection and Increased Sporadic Breast Carcinoma Risk: A Meta-Analysis

OBJECTIVE

An association of Epstein-Barr virus (EBV) infection with breast carcinoma (BC) risk has so far been disputed in the literature. Therefore, we performed a meta-analysis to clarify this relationship.

MATERIALS AND METHODS

An electronic database search for eligible case-control studies was performed using PubMed, Embase, Web of Science, the Cochrane Library, CNKI, and Wanfang Data until May 17, 2018. The pooled OR and 95% CI were used to estimate the relationship between EBV infection and BC risk using a fixed or random-effects model depending on heterogeneity. Subgroup analysis and meta-regression were used to explore the heterogeneity. Publication bias was assessed using Egger's and Harbord's tests.

RESULTS

A total of 16 studies with 1,279 patients and 814 controls were reviewed based on our inclusion and exclusion criteria. Compared with the control group, EBV infection had a significant association with BC risk (OR 4.75, 95% CI 2.53-8.92, p < 0.01) with significant heterogeneity observed (I2 = 65.3%). The subgroup analysis revealed that region and tissue type might explain potential sources of heterogeneity. The sensitivity analyses yielded stable results. No significant publication bias was observed.

CONCLUSION

The current results suggest that EBV infection is significantly associated with increased risk of BC.

Epstein-Barr virus and risk of breast cancer: a systematic review and meta-analysis

Despite the numerous publications regarding the role of Epstein-Barr virus (EBV) in breast cancer development, the topic has still remained controversial. The aim of the meta-analysis was to estimate the overall prevalence of EBV in the breast cancer population, and to investigate the association between EBV and breast cancer risk. The overall prevalence of EBV was calculated 26.37% (95% CI: 22-31%) from the 44 included studies. Meta-analysis of 30 case-control studies showed that the pooled association between EBV and risk of breast cancer is odds ratio 4.74 (95% CI: 2.92-7.69; Z = 6.30; p < 0.0001). Our analyses indicate a strong statistical relationship between EBV infection and risk of breast cancer, suggesting a potential role of EBV infection in the development of breast cancer.

Frequency of Epstein–Barr Virus DNA in Formalin-Fixed Paraffin-Embedded Tissue of Patients with Ductal Breast Carcinoma

Background: Ductal carcinoma is one of the most common breast cancer (BrC) among the women in the world. Several factors may involve in establishment of breast cancer. The role of viral infections have been investigated in BrC, Among them the association of Epstein Barr virus have been reported in the patients with breast cancer type ductal carcinoma. Thus this study was conducted to evaluate the rate of Epstein Barr virus in women with breast cancer type ductal carcinoma. Material and methods: A total of 72 formalin-fixed paraffin-embedded tissue blocks samples were collected from 37 (51.38%) women with breast cancer type ductal carcinoma and 35 (48.61%) samples of breast with fibro adenoma as control group. The DNA was extracted for all the samples. The detection of EBNA 3C EBV DNA was done by nested PCR. The results of positive were sequenced to confirm PCR product and determine EBV genotypes. Results: About 10/37 (27.02%) samples of ductal breast carcinoma were showed positive for EBNA 3C EBV DNA while 4/35 (11.42%) of fibro adenoma were positive for EBNA 3C EBV DNA (p= 0.095). Randomly 7 PCR products were sequenced and the results of sequencing EBNA 3C shows, the detected EBVDNA were type 1 EBV type. Conclusion: This study shows high prevalence of 27.02% EBV DNA type 1 was found in formalin-fixed paraffin-embedded tissue of Patients with ductal breast carcinoma. The outcomes of this study suggesting that EBV might have a significant role in breast cancer in Ahvaz city, south west region of Iran. However the expression of EBV oncoproteins ,EBNA1, LMP1, and LMP2 require to be determined with ductal carcinoma cells. About 72.97% breast samples showed negative for EBVDNA. The role other viruses including Human cytomegalovirus, papilloma viruses and Merkel viruses are required to be investigated in further studies.

Involvement of a mouse mammary tumor virus (MMTV) homologue in human breast cancer: Evidence for, against and possible causes of controversies

Breast cancer (BC) is a complex and heterogeneous disease whose evolution depends on the tumor-host interaction. This type of cancer occurs when the mammary cells begin to grow wildly and become able to invade nearby tissues and/or promote metastases. Mouse mammary tumor virus (MMTV) is the accepted etiological agent of mammary tumors in mice. The identification of MMTV-like sequences and antigens in human mammary carcinoma has supported the theory that a virus homologous to MMTV (namely, HMTV) may be involved in human BC, but the role of retroviral elements in this disease remains elusive, as results from different research groups were contradictory. In the present review we present works for and against the involvement of HMTV in BC and discuss possible causes of divergences among studies. In the final section we fit current data regarding this issue to stablished causality criteria. We conclude that there is convincing data supporting the association of HMTV with BC, however there is still a need for epidemiological and basic research studies focusing on carcinogenic mechanisms for this virus in humans to fully understand its role in BC. This knowledge may open the way for the development of new preventive and therapeutic approaches in human BC.

Is human papillomavirus associated with breast cancer or papilloma presenting with pathologic nipple discharge?

PURPOSE

There are little data on the presence or interaction of human papillomavirus (HPV) in intraductal papilloma or Breast cancer (BC) presenting with pathologic nipple discharge (PND). The study aimed to determine whether the HPV-genotypes are identifiable in papilloma or carcinoma of the breast by real-time PCR with broad-spectrum genotyping.

METHODS

Formalin-fixed-paraffin-blocks obtained from the patients who were suffering from PND and underwent ductoscopic papilloma extraction (n = 27) or segmental/total mastectomy for cancer diagnosis (n = 18). HPV-DNAs were identified by PCR with broad-spectrum genotyping. Mc Nemar test was used to compare cancer-involved cases to normal-adjacent tissue concerning HPV positivity. Chi-Square test was used to analyze the association for receptor status in HPV positive cancer-involved cases.

RESULTS

The mean age (±SD) was 49 ± 16 in papilloma and 52 ± 14 in BC patients, respectively. We found high prevalence of HPV in papilloma and carcinoma: 29.6% (n = 8) and 44.4% (n = 8), respectively. The most common type identified in breast lesions was HPV-11, and the others were HPV- 6, -11, -39, and -82. Cancer-involved samples were more contaminated by HPV in comparison to normal-adjacent tissues (p = 0.016). In HPV positive cancer-involved cases, hormone receptors were found to be more positive than HER2-Neu (p = 0.035).

CONCLUSIONS

Our data suggest that HPV might be a causative agent for the development of papilloma and carcinoma of the breast in some cases presenting with PND. HPV positive breast cancers are more likely to be hormone positive. Further studies needed for validation regarding the integration of HPV-DNAs into the human genome that causes BC.

HPV infection and breast cancer. Results of a microarray approach

OBJECTIVES

Human papilloma virus (HPV) has been implicated in several types of epithelial cancer. The role of HPV in breast carcinogenesis has been a matter of debate fueled by conflicting reports in recent years. The aim of this study is to identify the prevalence of breast and cervical HPV infection in cancer patients by using a modern microarray approach.

MATERIALS AND METHODS

In the present prospective study, 201 breast cancer patients were included. For each patient a detailed medical history was taken and during the operation, under sterile conditions, samples were collected, from the tumour, the healthy adjacent breast tissue and any positive sentinel lymph nodes. In addition, for each patient a cervical sample was also collected. All samples were analysed for DNA of 24 types of HPV using a microarray technique.

RESULTS

Despite the high sensitivity of the technique used, no HPV DNA was identified in any of the breast or lymph node samples. Our analysis showed that patients with HPV positive cervical samples (28 cases) were more likely to have tumors with positive progesterone receptors (p=0.041) and were also more likely to have two or three positive lymph nodes (p=0.002).

CONCLUSION

In the present study, a combination of careful sample collection and a very sensitive microarray approach showed no correlation between HPV and breast cancer. However some characteristics of the breast tumors were different among patients with HPV DNA in their cervical samples.

Risks and protective factors for triple negative breast cancer with a focus on micronutrients and infections

Triple negative breast cancer (TNBC) is an aggressive form of breast cancer (BC) with a poor prognosis. Second, patients cannot benefit from targeted therapy, except for those with BRCA1/2 mutations, for whom poly (ADP-ribose) polymerase (PARP) inhibition therapy using olaparib has recently been approved. As global priorities continue to be epidemiological analysis of BC risk factors and early diagnosis, this review focuses on the risks and protective factors associated with TNBC. A PubMed keyword search for new knowledge on the risks and protective factors for TNBC was carried out. We also found statistical information from current online databases concerning the estimated incidence, prevalence and mortality worldwide of this cancer. Traditional risk factors for BC and TNBC are those related to reproduction such as the age of menarche, age of first birth, parity, breastfeeding and age at menopause. Attention needs to be paid to familial BC, weight control, alcohol consumption and regular physical activity. Epidemiological studies on TNBC provide evidence for protective factors such as regular consumption of soya, seafood, green tea, folic acid and vitamin D. Potential risk factors may include night work and viral infectious agents like human papillomavirus (HPV) and Epstein-Barr virus (EBV). Droplet digital methylation-specific PCR (ddMSP) is a possible new screening method for detection of BC including TNBC. Further research is necessary to validate these new factors.

Epstein-Barr Virus and Human Papillomaviruses Interactions and Their Roles in the Initiation of Epithelial-Mesenchymal Transition and Cancer Progression

Oncoviruses are implicated in around 20% of all human cancers including both solid and non-solid malignancies. Epstein–Barr virus (EBV) and human papillomaviruses (HPVs) are the most common oncoviruses worldwide. Currently, it is well established that onco-proteins of EBV (LMP1, LMP2A, and EBNA1) and high-risk HPVs (E5 and E6/E7) play an important role in the initiation and/or progression of several human carcinomas, including cervical, oral, and breast. More significantly, it has been recently pointed out that viral onco-proteins of EBV and high-risk HPVs can be co-present and consequently cooperate to initiate and/or amplify epithelial–mesenchymal transition (EMT), which is the hallmark of cancer progression and metastasis. This could occur by β-catenin, JAK/STAT/SRC, PI3k/Akt/mTOR, and/or RAS/MEK/ERK signaling pathways, which onco-proteins of EBV and HPVs share. This review presents the most recent advances related to EBV and high-risk HPVs onco-proteins interactions and their roles in the progression of human carcinomas especially oral and breast via the initiation of EMT.

Prevalence of Mouse Mammary Tumor Virus (MMTV)-like sequences in human breast cancer tissues and adjacent normal breast tissues in Saudi Arabia

BACKGROUND

Breast cancer is considered the most common cancer in women worldwide and is the leading cause of cancer mortality. Sequences similar to Mouse Mammary Tumor Virus (MMTV) were detected in human breast cancer in several studies from different geographical areas. However, the role played by this virus in breast cancer tumorigenesis is not completely understood. These MMTV-like sequences were found to be associated with breast cancer of more malignant types. The aim of this study is to determine the prevalence of MMTV-like envelope gene (env) positivity in breast cancer and non-cancerous breast tissue from Saudi Arabia.

METHODS

Detection of MMTV-like env proviral sequences was done using newly designed primers for conventional polymerase chain reaction (PCR). One hundred nighty four samples were collected from 103 females with breast cancer in addition to 51 control breast tissue obtained from individuals without cancer. We additionally investigated the association of proviral positivity with age of the patients, grade of breast cancer and presence of lymph node metastasis. The results were confirmed by sequencing.

RESULTS

The prevalence of MMTV-like env proviral positivity was 8.7% (9/103). MMTV env proviral sequences were detected in 5.9% (6/101) of breast cancer tissues and 9.7% (9/93) of non-cancerous adjacent tissues obtained from the same patients. None of the 51 control sample showed positive result for the MMTV env gene. No significant association was found between detection of the virus and the age of the patient, grade of the cancer or presence of metastasis.

CONCLUSION

We document the presence of low frequency of MMTV env provirus sequence among breast cancer patients from Saudi Arabia. Further studies are needed to explore the role of the MMTV in breast cancer.

Oncogenic Viruses and Breast Cancer: Mouse Mammary Tumor Virus (MMTV), Bovine Leukemia Virus (BLV), Human Papilloma Virus (HPV), and Epstein-Barr Virus (EBV)

Background

Although the risk factors for breast cancer are well established, namely female gender, early menarche and late menopause plus the protective influence of early pregnancy, the underlying causes of breast cancer remain unknown. The development of substantial recent evidence indicates that a handful of viruses may have a role in breast cancer. These viruses are mouse mammary tumor virus (MMTV), bovine leukemia virus (BLV), human papilloma viruses (HPVs), and Epstein–Barr virus (EBV-also known as human herpes virus type 4). Each of these viruses has documented oncogenic potential. The aim of this review is to inform the scientific and general community about this recent evidence.

The evidence

MMTV and human breast cancer—the evidence is detailed and comprehensive but cannot be regarded as conclusive. BLV and human breast cancer—the evidence is limited. However, in view of the emerging information about BLV in human breast cancer, it is prudent to encourage the elimination of BLV in cattle, particularly in the dairy industry. HPVs and breast cancer—the evidence is substantial but not conclusive. The availability of effective preventive vaccines is a major advantage and their use should be encouraged. EBV and breast cancer—the evidence is also substantial but not conclusive. Currently, there are no practical means of either prevention or treatment. Although there is evidence of genetic predisposition, and cancer in general is a culmination of events, there is no evidence that inherited genetic traits are causal.

Conclusion

The influence of oncogenic viruses is currently the major plausible hypothesis for a direct cause of human breast cancer.

Breast cancer: Lesser-known facets and hypotheses

Breast cancer is the most common cancer in females. The deteriorating environment, and lifestyle flaws are raising the frequency of this cancer. Existing therapies are not universally-effective, and they cause side effects, relapses, and high mortality rate. Alternative medications may be milder, but are less effective or are inadequate for a complex disease like the breast cancer. So, it requires the understanding that drugs are not the solution of this cancer, but prevention is the sustainable solution. In the past decades, an enormous quantum of insights on this disease has been obtained. A lifestyle based on the template of estrogenic compounds and, the resultant endocrine disruption, and acidosis, is elevating aromatase level, promoting the deleterious forms of estrogen, and inducing epithelial proliferation. This review provids a holistic account of breast cancer as a inflammatory endocrinopathy, and how it can be curbed by discipline, and awareness.

Multiple oncogenic viruses are present in human breast tissues before development of virus associated breast cancer

Background

Multiple oncogenic viruses including, mouse mammary tumor virus, bovine leukemia virus, human papilloma virus, and Epstein Barr virus, have been identified as separate infectious pathogens in human breast cancer. Here we demonstrate that these four viruses may be present in normal and benign breast tissues 1 to 11 years before the development of same virus breast cancer in the same patients.

Methods

We combined the data we developed during investigations of the individual four oncogenic viruses and breast cancer. Patients who had benign breast biopsies 1–11 years prior to developing breast cancer were identified by pathology reports from a large Australian pathology service (Douglas Hanly Moir Pathology). Archival formalin fixed specimens from these patients were collected. The same archival specimens were used for (i) investigations of mouse mammary tumour virus (also known as human mammary tumour virus) conducted at the Icahn School of Medicine at Mount Sinai, New York and at the University of Pisa, Italy, (ii) bovine leukemia virus conducted at the University of California at Berkeley,(iii) human papilloma virus and Epstein Barr virus conducted at the University of New South Wales, Sydney, Australia.

Seventeen normal breast tissues from cosmetic breast surgery conducted on Australian patients were used as controls. These patients were younger than those with benign and later breast cancer.

Results

Standard and in situ polymerase chain reaction (PCR) methods were used to identify the four viruses. The detailed methods are outlined in the separate publications.: mouse mammary tumor virus, human papilloma virus and Epstein Barr virus (Infect Agent Cancer 12:1, 2017, PLoS One 12:e0179367, 2017, Front Oncol 5:277, 2015, PLoS One 7:e48788, 2012).

Epstein Barr virus and human papilloma virus were identified in the same breast cancer cells by in situ PCR.

Mouse mammary tumour virus was identified in 6 (24%) of 25 benign breast specimens and in 9 (36%) of 25 breast cancer specimens which subsequently developed in the same patients.

Bovine leukemia virus was identified in 18 (78%) of 23 benign breast specimens and in 20 (91%) of 22 subsequent breast cancers in the same patients.

High risk human papilloma viruses were identified in 13 (72%) of 17 benign breast specimens and in 13 (76%) of 17 subsequent breast cancers in the same patients.

Epstein Barr virus was not identified in any benign breast specimens but was identified in 3 (25%) of 12 subsequent breast cancers in the same patients.

Mouse mammary tumour virus 3 (18%), bovine leukemia virus 6 (35%), high risk human papilloma virus 3 (18%) and Epstein Barr virus 5 (29%) were identified in 17 normal control breast specimens.

Conclusions

These findings add to the evidence that multiple oncogenic viruses have potential roles in human breast cancer. This is an important observation because evidence of prior infection before the development of disease is a key criterion when assessing causation.